In baghouse filters of the stated type, the filter bags are suspended in a transverse partition within the filter housing and the gaseous medium is caused to flow through the housing in a direction such that the medium flows from the outside toward the inside of the filter bags and deposits the particulate matter on the exterior surface of the filter bags. Means is provided to periodically dislodge the particulate matter which has built up upon the exterior surfaces of the filter bags and the dislodged particulate matter is discharged from the bottom of the filter housing. A conventional apparatus for effecting such dislodgement is a bank of nozzles which are periodically activated to direct jets of air into the interiors of the filter bags. The filter bags may be cleaned sequentially or in unison by suitable programming of the activation of the jets. In order to prevent the bags from collapsing during the operation of the filter, cages or frames are inserted into the bags to maintain the bags open and prevent them from collapsing which would impede the flow of medium therethrough.